Insulated conductor



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J Hie. O'NEILL.

" (Ro mmy v INSULATED connuc'ron. No. 533,607

Patented Feb. 5, 1895.

' WITNESSES:

' JNVENTOI? A TTORNE).

2% Slit); f fitence pp U ITED STATES P TENTK OFFICE.

HENRY c. ONEILL, or BOSTON, MASSACHUSETTS, ASSIGNOR To EDWARD JEWELL, OF'SAME PLACE, AND-CHARLES w. w LpH, or STOUGHTON, MASSACHUSETTS. v

INSULATED CONDUCTOR.

EEGIFIGATION forming part of Letters Patent No. 533,607, dated February 5., 1 895.

Application filed March 22,1894. Serial No- 4,7l4- (No modeLl To all whom it may concern.- represents a similar view of the said resist- Be it known that I, HENRY G. ONEILL, a ancesurrounded by a protective covering and citizen of the United States, residing at Bosan external waterproof covering as described. ton, in the county of Sufiolk and State of Fig. 3 is a broken longitudinal 'view of the 5 Massachusetts, have invented certain new form shown in Fig. 2. and useful Improvements in Means for Insu- A designates the resistance, B the inner laing Conductors and Resistances; and I do coating and C the-outer coating. The comhereby declare the following to beafull, clear, position of the former as already stated conand exact description of the invention, such sists of a paste made from some finely pow- 10 as will enable others skilled in the art to which dered silicate or silicates molded on the said it appertains to make and use the same. resistance, It does not require for its solidi- The object of this invention is to protect fication any such extreme heat as is necessary conductors and resistances, especially those in firing enamel, but forms a cement having used in rheostats and electric heaters, from a high coetficient of heat, forming a close con- 15 injury by oxidation, fusion, electrolysis, short tact with the resistance and absorbing grad cir uits or crystallization. Such evils are ually the heat thereof, so as to prevent its often caused by condensation of atmospheric fusion and anyinj urious overheating. When moisture, by dampness due to evaporization the heating current is withdrawn, this com in ironing, by the water used in cleaning arout by reason of its high specific heat cools 2o ticles or utensils to which the resistance is atthe resistance by conduction and exerts a pretached, by the action of electrical currents, servative annealing influence, which will pretending to crystallize the conductor or resistvent crystallization and brittleness; whereby ance and make it brittle, and bythe dangerswafter long use the resistance will be found due to abnormal currents or changes of curstill in its normal state, bright, and not easily 2 5 rent which will sometimes occur. Burning broken. Such a cement, however, without out most often occurs at the .junction of aother safeguard, is not impervious to water, feed wire with the resistance. This also, by and therefore means of waterproofing it must the same means, it is proposed to remedy. be employed. To'thisend, I incase the said To. this end, I inelose the resistance 'in a paste coating B in an out coatin C, Fig. 2, which 30 of powdered silicates, preferably silicate o a be a mix ue me amen and dilute 8o ma nesia silicate of soda, oramixtureo e aicid; or the same may be atiwo. This covering will protect the resisttamed by mixing these waterproof ingreance against burning out and preserve it by dients with the paste first above described. an annealing action and by gradually con- Sometimes, to secure better adhesion to the 35 ducting the heat away from it; also it will resistance I add powdered black oxide of not crack nor flake away so as to expose the manganese and silicate of potassium to the wire; but on the other hand such a covering said paste. A is not impervious to water, and, by itself, in I am aware that waterproof and fireproof volves the risk of oxidizing the resistance or enamel has been used to insulate resistances;

40 short circuiting the current. To guard but this is inapplicable to many delicate deagainst this I provide the said covering with vices by reason of the intense heat required means of waterproofing the same. Such in such processes. Morever it does not exermeans consist of a wate n coain a i lied cise any annealing influence or conduct away outsfle of i t or the ingre ieu s o suc coat the heat sufliciently to save the wire from gfigrnwoe mixed with the paste aforesaid, fusion in a strong intense current; also, it

answering the same purpose. cracks and scales 0E exposing the enclosed In the accompanying drawings Figure 1 resistance to injury. represents a cross-section of a resistance hav- Protoxidepf magngsium, fire-play, plaster ing the form of a straight bar, surrounded by of paris? and asbestos have been used as in- 50 a protective coating as aforesaid; and Fig. 2 sulators, but all are permeated by water and too COA Tins'oii mm air and crack or shrink under heat.\ Soapstone has likewise been formed into acovering for electric codnctors, and is free from some of these defects, but will not-by itself 5 adequately protect the wire or resistance against oxidation and the other evils due to access of air and moisture.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, isv 1. A covering for electric conductors and resistances consisting of a paste composed of powdered silicates and rendered waterproof substantially as set forth.

2. A covering for electric conductors and resistances consisting of insulating cement having a high specific heat and rendered waterproof substantially as set forth.

3. A covering for resistances consisting of two coats, the inner coat being composed of a 20 paste of powdered silicates and the outer coat composed of a water proofing mixture for the purpose set forth.

4. A covering for resistances consisting of two coats, the inner coat being composed of a 2 5 mixture of silicate of magnesia and silicate of soda in solution and the outer coat consisting of a mixture of lime albumen dilute and lactic acid substantially as set forth.

In testimony whereof I afiix my signature 0 in presence of two witnesses.

HENRY G. ONEILL.

Witnesses:

EDWIN W. PIERCE, PELETIAH R. TRIPP. 

